Everything old is new again, as they say in the fashion world:
The “warm little pond” idea was a mere suggestion when Darwin wrote to Joseph Hooker in 1871, a year before his death, but it was too vague to be taken seriously. Over 50 years later, in 1924, Alexander Oparin developed the idea with a little more rigor. He did so with the help of J.B.S. Haldane, speculating on how building blocks of life could be contained inside temporary droplets of organic goo. Wikipedia says, “For decades the theory of Oparin and Haldane was the leading approach to the origin of life question,” adding, “However, the lack of any mechanism by which coacervates can reproduce leaves them far short of being living systems.”
Also lacking was any mechanism for the transition from chance droplets to the elaborate lipid membranes in modern cells, with their active transport machines and sensory cilia. Considering that membranes are formed and regulated under the direction of nuclear codes, their likeness to chance droplets seems as strained as comparing cells to soap bubbles.“Not Oparin’s Coacervates Again!” at Evolution News and Science Today
But, we are told, the theory has been resurrected in a paper in PNAS, featuring “microdroplets” which are more stable when diluted (paywall):
The word “could” appears 34 times in the paper, “suggests” and similar words 20 times, “possible” and similar words 13 times, “likely” 11 times, “may have” 8 times, and “perhaps” 3 times. The paper includes 12 movies of spherical drops bouncing around and occasionally merging. OK, so? You can observe that in the kitchen sink with soap bubbles in a dish.“Not Oparin’s Coacervates Again!” at Evolution News and Science Today
In origin of life studies, that’s par for the course. It won’t change because it can’t.
Our physics color commentator, Rob Sheldon, offers some thoughts:
it would seem to me that rather pure concentrations of alpha-hydroxy acid was used to make the gel. The drying was needed to polymerize it, and then the “droplets” formed little cell-sized globs of protoplasm in which presumably other important lifelike reactions could occur.
None of these steps is remotely likely. Not one. The density of any complex hydrocarbon is parts per million in a random soup, which just is not going to polymerize with itself, but with every other contaminant of equal or greater concentration. So the mere fact that purified laboratory chemicals are involved in this reaction is a non-starter for OOL. Always.
Ignoring all the problems of the formation of unstable molecules, the destruction of unstable molecules, or the reason why carbonaceous chondrites have these molecules in the first place (life), and just assuming we have these chemicals in the concentrations actually observed, we still don’t have a chance at OOL. Remember Fred Hoyle’s challenge–put your favorite bacteria cultures in a blender, destroy every cell. Now you have all the right chemicals in the right proportions. How long will you have to wait until life spontaneously appears? If the wait is longer than 10 minutes, than the vastly more diluted ocean cannot spontaneously create life in the 4 billion years of the Earth’s existence. It’s just math.
Nor is this scenario remotely original–just about everyone uses the wet/dry cycle to get polymerization to go. The resulting gel or goo is the old 1800 “protoplasm” theory about OOL. We’ve so run out of ideas we’re now revisiting scenarios that are 2 centuries old.
And finally, there’s something superstitious about putting form before function; demanding that the gel form cell-shaped droplets before it can become alive. It’s the same idea that gingerbread cookie dough shaped like a man has a better chance at becoming alive than when shaped like a cookie. Yet this is the level of discussion in OOL. Pathetic really.
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See also: The Science Fictions series at your fingertips – origin of life What we do and don’t know about the origin of life.